Microstructures and methods of making and using thereof

ABSTRACT

A method of manufacturing a structure, the method comprising: obtaining a flowable liquid comprising a homogenous mixture of an active material and a binding material; generating a plurality of droplets from the flowable liquid; and depositing the plurality of generated droplets on a support, wherein the plurality of droplets self-assemble to form a continuous structure, wherein the continuous structure comprises a plurality of microstructure units, and wherein the active material and the binding material self-segregate to form a non-uniform distribution of the active material and the binding material in each of the units.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Pat. Application No.17/591,878, filed Feb. 3, 2022, which claims the benefit of U.S.Provisional Application No. 63/199,950, filed Feb. 4, 2021. The entirecontents of the above-identified applications are hereby fullyincorporated herein by reference.

TECHNICAL FIELD

The subject matter disclosed herein is generally directed tomicrostructures and methods of making and using thereof.

BACKGROUND

Many articles of manufacture or their components have various activematerials coated on supports that are important for certain functions ofthe articles. The current methods of coating involve milling the activematerials, typically in particulate-form, along with a binder materialin a fluid to produce a flowable liquid that could then be sprayed,blade-cast, dip-coated, screen printed, etc., onto a support. The roleof the binder is to provide physical integrity to the coated structureand adhesion to the support. A drying process could follow the coatingstep to drive off the fluid. The resulting coating microstructures aretypically in the micrometer scale.

Alternatively, the active materials could be vaporized, eitherphysically at high temperatures or chemically in a reactive vapor-form,onto a support. These vapor-deposited coatings are typically in thenanometer scale.

All these coating methods result in homogeneous coating microstructureswhere the active materials are distributed uniformly throughout thecoating.

In some applications, such as in a battery electrode (e.g., an anodeand/or cathode) may have a metal foil, a metallized polymer foil, or anyother material capable of conducting electricity as support, on which alayer of a composite material containing one or more active materialsand other elements is coated. The battery can be a primary or secondarybattery, such as a lithium-ion battery or any other present or futureelectrochemical formula, having a structure of anode 1 electrode,separator and cathode electrode. Such a battery can use a liquid, gel,solid or any other type of electrolyte responsible for transporting ionsbetween the electrodes.

Existing techniques for electrode coating produce a homogeneousdistribution of the active material and elements with no control at themicrometer or nanometer scale where the particles of the activematerial, the binding material or current enhancer are locatedspatially. Conventional electrodes are made from randomly sized,randomly oriented, and relatively poorly packed active materials, whichcreate long and indirect paths through the electrolyte for the lithiumions to travel. In materials science these paths are described as“tortuous.” [1] Gene Berdichevsky, Gleb Yushin, “The Future of EnergyStorage, Towards a Perfect Battery with Global Scale” (SilaNanotechnologies, Inc., Sep. 2, 2020). As described in [1], thesetortuous paths are akin to not having rows of seats in the auditorium,just randomly distributed clusters of seats. Further, conventionalelectrodes also use an excessive amount of inactive materials, bothpolymer binders and conductive additives, because it is difficult todistribute those inactive materials to only where they are needed in theelectrode, which are the points where particles touch one another.

Another example is in catalysis, it may be advantageous to have theactive catalyst materials placed at or near the surface of the coatingto enable chemical reactants to easily reach the active catalytic sitesand for products of the chemical reaction to be easily transported awayonce the chemical reaction is completed.

With a homogeneous catalyst coating, the active catalyst sites that areplaced deeper in the coating structure are less accessible to thechemical reactants and the products of the chemical reaction will alsotake longer to be transported away. Therefore, a uniform distribution ofactive catalyst sites does not always provide the optimum structure forcatalysis.

Yet another example is in controlled release application where acompound, or a drug, is desired to be released in a controlled manner ina transport medium, such as a body fluid. With a homogeneous coating ofthe active drug material on a support, those active drug material placedat or near the surface of the coating will be released more quickly thanthose active drug material buried deeper in the coating microstructureleading to a non-uniform release of the active drug material. In thiscontrolled release example, it may be more desirable to purposely placethe active drug material deeper in the coating microstructure and not atthe surface to effect a more uniform release of the active drugmaterial.

SUMMARY

Thus, there is a need for producing coating materials with definedmicrostructures in which the spatial distribution of the activematerials within the microstructures are controlled to provide optimalfunctions of the coating materials and the coated articles.

These and other aspects, objects, features, and advantages of theexample embodiments will become apparent to those having ordinary skillin the art upon consideration of the following detailed description ofillustrated example embodiments.

In one aspect, the present disclosure provides a method of manufacturinga structure, the method comprising: obtaining a flowable liquidcomprising a homogenous mixture of an active material, and a bindingmaterial; generating a plurality of droplets from the flowable liquid;and depositing the plurality of generated droplets on a support, whereinthe plurality of droplets self-assemble to form a continuous structure,wherein the continuous structure comprises a plurality of microstructureunits, and wherein the active material and the binding materialself-segregate to form a non-uniform distribution of the active materialand the binding material in each of the units.

In some embodiments, the active material imparts a physical, thermal,chemical, catalytic, electrical, magnetic, radioactive, photonic,biological, or combinations thereof property to the continuousstructure. In some embodiments, the active material imparts anelectrical property to the continuous structure, and the active materialcomprises one or more of a conductor, semiconductor, or insulator. Insome embodiments, the active material distributes within an area in eachmicrostructure unit bounded by the respective unit. In some embodiments,the active material distributes non-uniformly within the area of each ofthe units.

In some embodiments, the binding material is an organic material,inorganic material, or combinations thereof. In some embodiments, thebinding material self-segregates to accumulate at edges of the units. Insome embodiments, the active material accumulates adjacent to a boundaryformed by the binding material. In some embodiments, a center of arespective unit is hollow and contains no active material or bindingmaterial. In some embodiments, the binding material comprises a liquidcarrier. In some embodiments, the liquid carrier comprises an inorganiccomposition or organic composition.

In some embodiments, the method further comprises polymerizing thebinding material. In some embodiments, the polymerizing is performed byheat or irradiation.

In some embodiments, the flowable liquid further comprises a materialconfigured to change a surface charge of at least one of the activematerial or the binding material. In some embodiments, the materialconfigured to change a surface charge of at least one of the activematerial or the binding material comprises a coupling agent. In someembodiments, the flowable liquid further comprises a material configuredto change a zeta potential of the active material. In some embodiments,the material configured to change a zeta potential of at least one ofthe active material comprises a surfactant or a dispersant.

In some embodiments, the generated droplets have an average volume inthe range of 0.1 picoliters to 3000 picoliters. In some embodiments, theunits have an average diameter from 0.04 micrometers to 2000micrometers. In some embodiments, the support comprises a metallic film,metallized plastic film, metallized polymer film, glass film, ceramicfilm, polymer film, or paper.

In some embodiments, the method further comprises controlling sizes ofthe droplets. In some embodiments, the controlling sizes of the dropletscomprises applying force to the flowable liquid. In some embodiments,the force comprises mechanical pressure, collision with another liquidor fluid, ultrasonic waves, electrical charge, or a combination thereof.In some embodiments, the controlling sizes of the droplets comprisesforcing the flowable homogenous liquid through orifices or openings ofdifferent sizes. In some embodiments, the method further comprisescontrolling at least one of the volume or a position of the droplets bya digitally controlled tool. In some embodiments, the flowable liquidhas a viscosity from 3 centipoise to 1500 centipoise.

In some embodiments, the continuous structure comprises a layercomprising a plurality of the units along a planar surface of thesupport. In some embodiments, the continuous structure comprises aplurality of stacked layers along a planar surface of the support andeach stacked layer comprises a plurality of the units. In someembodiments, an average diameter in a first layer of the plurality ofstacked layers is different than an average diameter of themicrostructure units in a second layer of the plurality of stackedlayers. In some embodiments, a first layer of the plurality of stackedlayers comprises one or more of: a material that is different than oneor more materials in a second layer of the plurality of stacked layers,or an active material that is the same as an active material in thesecond layer of the plurality of stacked layers, and the active materialin the first layer has having a different physical, chemical, catalytic,electrical, magnetic, radioactive, photonic, biological, or combinationsthereof characteristic than the same active material in the second layerof the plurality of stacked layers.

In some embodiments, each microstructure unit comprises an area boundedby at least three sides. In some embodiments, a subset of the pluralityof microstructure units comprise an area bounded by six sides to form ahoneycomb cell. In some embodiments, the subset comprises a majority ofthe plurality of microstructure units. In some embodiments, each unithas a vertical aspect ratio equal to or greater than 1.

In some embodiments, the active material is a compound comprisinglithium. In some embodiments, the active material intercalates lithiumions or has a conversion reaction in the presence of lithium ions. Insome embodiments, the support is comprised in a cathode, anode,separator, solid electrolyte, or semi-solid electrolyte.

In some embodiments, the active material is an active catalyst capableof causing or accelerating a chemical reaction between reactants andwherein the reactants and a product of the chemical reaction aretransported through the microstructure units. In some embodiments, theactive material is an active adsorbent capable of selectively binding toan adsorbate and wherein a medium carrying the adsorbate is transportedthrough the microstructure units. In some embodiments, the activeadsorbent gives a response when binding to an adsorbate, and wherein theresponse comprises a change in at least one of a physical, chemical,electrical, optical or magnetic property of the active adsorbent. Insome embodiments, the active material is an active carrier of acompound, and wherein at least a part of the compound can be released ina controlled manner when contacted with a transport medium, and whereinthe transport medium is transported through the microstructure units. Insome embodiments, the active material is an active carrier of aphoto-sensitive compound, and wherein the photo-sensitive compound givesan optical response when excited photonically. In some embodiments, theactive material is an active carrier of a magnetic-sensitive compound,and wherein the magnetic-sensitive compound gives a magnetic responsewhen excited magnetically. In some embodiments, the active material isan active carrier of a pigment, and wherein the pigment gives an opticalresponse when excited with visible, ultraviolet or infrared light. Insome embodiments, the active material self-segregates to accumulate atedges of the units.

In another aspect, the present disclosure provides a structurecomprising a plurality of microstructure units, wherein each of theunits comprises a binding material self-segregated from an activematerial to form a non-uniform distribution of the binding material andthe active material in each of the units. In some embodiments, theactive material imparts a physical, thermal, chemical, catalytic,electrical, magnetic, radioactive, photonic, biological property, or acombination thereof to the structure. In some embodiments, the activematerial is distributed within an area in each microstructure unitbounded by the respective unit. In some embodiments, the active materialis distributed non-uniformly within the area of each unit.

In some embodiments, the binding material comprises an organic material,an inorganic material, or a combination thereof. In some embodiments,the binding material self-segregates to accumulate at edges of theunits. In some embodiments, the active material accumulates adjacent toa boundary formed by the binding material. In some embodiments, a centerof a respective unit is hollow and contains no active material orbinding material. In some embodiments, the units have an averagediameter from 0.04 micrometers to 2000 micrometers.

In some embodiments, the structure comprises a continuous planar layer.In some embodiments, the structure comprises a plurality of stackedplanar layers. In some embodiments, a first layer comprises an activematerial that is the same as an active material of a second layer of theplurality of stacked layers and the first layer has different particlesize characteristics than the second layer of the plurality of stackedlayers.

In some embodiments, each microstructure unit comprises an area boundedby at least three sides. In some embodiments, a subset of the pluralityof microstructure units comprise an area bounded by six sides to form ahoneycomb cell. In some embodiments, the subset comprises a majority ofthe plurality of microstructure units. In some embodiments, each unithas a vertical aspect ratio equal or greater than 1.

In some embodiments, the active material intercalates lithium ions orhas a conversion reaction in the presence of lithium ions. In someembodiments, the active material is an active catalyst capable ofcausing or accelerating a chemical reaction between reactants andwherein the reactants and a product of the chemical reaction aretransported through the microstructure units. In some embodiments, theactive material is an active adsorbent capable of selectively binding toan adsorbate and wherein a medium carrying the adsorbate is transportedthrough the microstructure units. In some embodiments, the activeadsorbent gives a response when binding to an adsorbate, and wherein theresponse comprises a change in a physical, chemical, electrical, opticaland magnetic property of the active adsorbent. In some embodiments, theactive material is an active carrier of a compound, and wherein at leasta part of the compound can be released in a controlled manner whencontacted with a transport medium, and wherein the transport medium istransported through the microstructure units. In some embodiments, theactive material is an active carrier of a photo-sensitive compound, andwherein the photo-sensitive compound gives an optical response whenexcited photonically. In some embodiments, the active material is anactive carrier of a magnetic-sensitive compound, and wherein themagnetic-sensitive compound gives a magnetic response when excitedmagnetically. In some embodiments, the active material is an activecarrier of a pigment, and wherein the pigment gives an optical responsewhen excited with visible, ultraviolet or infrared light.

In another aspect, the present disclosure provides an article ofmanufacture comprising the structure described herein of any one orcombination thereof. In some embodiments, the article further comprisesa support coated by the structure. In some embodiments, the supportcomprises a metallic film, metallized plastic film, metallized polymerfilm, glass film, ceramic film, polymer film, or paper.

In some embodiments, the article is an electrochemical cell. In someembodiments, the electrochemical cell comprises an electrode comprisingthe structure. In some embodiments, the structure comprises a conductivematerial. In some embodiments, the support is comprised in a cathode,anode, separator, solid electrolyte, or semi-solid electrolyte.

In another aspect, the present disclosure provides a compositioncomprising a flowable liquid comprising a homogenous mixture of anactive material and a binding material, wherein, when droplets of thecomposition are deposited on a support, the droplets self-assemble toform a continuous structure, wherein the continuous structure comprisesa plurality of microstructure units, and wherein the binding and activematerials self-segregate to form a non-uniform distribution of materialsin each of the units.

In some embodiments, the active material imparts a physical, thermal,chemical, catalytic, electrical, magnetic, radioactive, photonic,biological property, or a combination thereof to the continuousstructure. In some embodiments, the binding material comprises anorganic material, inorganic material, or a combination thereof. In someembodiments, the binding material self-segregates to accumulate at edgesof the units.

In some embodiments, the binding material comprises a liquid carrier. Insome embodiments, the liquid carrier comprises an organic composition,an inorganic composition, or a combination thereof.

In some embodiments, the flowable liquid further comprises a materialconfigured to change a surface charge of at least one of the activematerial or the binding material. In some embodiments, the materialconfigured to change a surface charge of at least one of the activematerial or the binding material comprises a coupling agent. In someembodiments, the flowable liquid further comprises a material configuredto change a zeta potential of the active material. In some embodiments,the material configured to change a zeta potential of the activematerial comprises a surfactant and/or a dispersant. In someembodiments, a mass ratio between the active material and the bindingmaterial is from 0.000001 to 1000000. In some embodiments, the flowableliquid has a viscosity from 3 centipoise to 1500 centipoise.

In another aspect, the present disclosure provides a method ofmanufacturing a structure, the method comprising: obtaining a flowableliquid comprising a homogenous binding material; generating a pluralityof droplets from the flowable liquid; and depositing the plurality ofgenerated droplets on a support, wherein the plurality of dropletsself-assemble to form a continuous structure, wherein the continuousstructure comprises a plurality of microstructure units, and wherein thebinding material self-segregates to form a non-uniform distribution ofthe binding material in each of the units.

In another aspect, the present disclosure provides a structurecomprising a plurality of microstructure units, wherein each of theunits comprises a binding material self-segregated to form a non-uniformdistribution of the binding material in each of the units. In anotheraspect, the present disclosure provides an article of manufacturecomprising the structure. In some embodiments, the article furthercomprises a support coated by the structure. In some embodiments, thesupport comprises a polymer film.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of embodiments of the invention and are incorporated inand constitute a part of this specification, illustrate embodiments ofthe invention and together with the description serve to explain theprinciples of embodiments of the invention.

FIG. 1 illustrates a process for manufacturing a structure, according tosome embodiments.

FIG. 2A shows a droplet 203 containing a homogeneous liquid containingactive materials 207 a and 207 b and a binding material 209, accordingto some embodiments.

FIG. 2B illustrates self-segregation of the active materials 207 a and207 b and the binding material 209 to form a non-uniform distribution ofthe active material and the binding material in a microstructure unit205, according to some embodiments.

FIG. 3 illustrates self-assembly and self-segregation of liquid droplets303 a-n to form a structure 330, according to some embodiments.

FIGS. 4A-4C illustrate cross sections of microstructure units 405 a-c,according to some embodiments.

FIG. 5 illustrates multiple layers 550 a-n of a structure 530, accordingto some embodiments.

FIG. 6 is a topographical optical image of a structure, according tosome embodiments.

FIG. 7 is a topographical scanning electron micrograph image of astructure, according to some embodiments.

FIG. 8A is a topographical scanning electron micrograph image of a priorart commercial electrode.

FIG. 8B illustrates an energy dispersive spectroscopy of the prior artcommercial electrode shown in FIG. 8A.

FIG. 9A is a topographical scanning electron micrograph image of astructure, according to some embodiments.

FIG. 9B illustrates the fluorine channel of an energy dispersivespectroscopy of the structure shown in FIG. 9A, according to someembodiments.

FIG. 10A illustrates a topographical scanning electron micrograph imageof a structure, according to some embodiments.

FIG. 10B illustrates an energy dispersive spectroscopy of the structureshown in FIG. 10A, according to some embodiments.

FIG. 11 is a schematic representation of the structure shown in FIGS.10A-10B.

FIG. 12 illustrates a structure with the binding material but not theactive material, according to some embodiments.

FIG. 13 is a chart comparing structures manufactured with two differentdrying processes, according to some embodiments.

FIG. 14 is a method of manufacturing a structure, according to someembodiments.

FIG. 15 is a method of manufacturing a structure, according to someembodiments

The figures herein are for illustrative purposes only and are notnecessarily drawn to scale.

DETAILED DESCRIPTION

The present disclosure provides a structure with microstructure unitswhose properties may be controlled during the manufacture process. Themanufacturing process may involve preparing a liquid comprising anactive material and a binding material that can be dispensed as dropletsonto a support, where such droplets may self-assemble to formmicrostructure units in a continuous coating. Furthermore, the bindingmaterial may self-segregate from the active material so that the activematerial and/or binding material non-uniformly distribute in each of themicrostructure units. The present disclosure further provides a methodof manufacturing the structure, with which the non-uniform distributionof the active material and/or the binding material may be controlled toform microstructure units with desired properties.

In some embodiments, the self-assembly and self-segregation of theactive material and the binding material may give rise to a number ofphenomena. The self-assembly of droplets, containing the active materialand the binding material, may create unique microstructure units in acontinuous coating. In some battery applications, the active materialmay comprise a lithium intercalation or conversion material, or otherelectrical charge carrying species, to form the cathode and/or the anodeelectrode. The self-segregation of the binding material that may notparticipate in ion diffusion, may greatly decrease the tortuosity of theconductive pathways, thereby creating an additional “secondary porenetwork” to enhance ion mass transport. This secondary pore network mayhave the effect of increasing the power density and charging speeds ofthe battery without compromising the energy density of the electrode.The self-segregation of the binding material to or near the edges of themicrostructure unit may add structure strength to the microstructuralunit, thereby increasing the mechanical integrity of the electrode.Also, the self-segregation of the active material may increase theparticle-to-particle contact of the active material, thereby increasingthe electrical conductivity of the electrode.

In some embodiments, the structure may be coated on an electrode of abattery. The physical properties of the microstructure of the electrodecoating may provide higher power density compared to an electrode coatedwith the same material but without the microstructure.

The applications of the method and the structure provided herein are notlimited to batteries. For example, the method and the structure may beused in catalyst applications, pharmaceutical products, aerospacetechnologies, medical devices, and consumer goods, among others. Forexample, in a catalyst application, deliberate placement of the activecatalyst materials near the surface of the microstructure units mayallow the chemical reactants easy access to the active catalyst siteswhile allowing products of the chemical reaction to be transported awayquickly from the active catalyst sites.

In one aspect, the present disclosure provides a method of manufacturingthe structure described herein. In general, the method may compriseobtaining a flowable liquid comprising an active material and a bindingmaterial (e.g., a homogenous mixture of an active material and a bindingmaterial), generating a plurality of droplets from the flowable liquid,and depositing the plurality of droplets generated from the flowableliquid on a support. When deposited on the support, the plurality ofdroplets may self-assemble to form a continuous structure, whichcomprises a plurality of microstructure units, and the active materialand the binding material may self-segregate to form a non-uniformdistribution of the materials in each of the units.

FIG. 1 illustrates a process for manufacturing a structure, according tosome embodiments. In this example, a nozzle 101 may be used to generateand dispense a plurality of droplets 103 of a composition formanufacturing the structure. The nozzle 101 may be controlled to movealong the x, y, and/or z directions to deposit the droplets 103 todesired locations on a support. FIG. 1 illustrates the process occurringover time, including at time intervals t₁-t₄, as described in furtherdetail below in connection with FIG. 3 .

In some embodiments, the composition for manufacturing the structure maycomprise a flowable liquid comprising an active material and a bindingmaterial. For example, the flowable liquid may comprise a homogenousmixture of an active material and a binding material.

In some embodiments, the flowable liquid may comprise a liquid carrier.For example, the binding material may comprise the liquid carrier. Whenthe composition is deposited on a support, the liquid carrier may beallowed to evaporate to facilitate the formulation of the structure. Insome examples, the liquid carrier may comprise an organic composition.For example, the liquid carrier may be an organic solvent, e.g.,N-Methylpyrrolidone. In some examples, the liquid carrier may comprisean inorganic composition. In some examples, the liquid carrier maycomprise a mixture or a combination of an organic composition and aninorganic composition.

In some embodiments, the flowable liquid may comprise a materialconfigured to change the surface charge of the active material and/orthe binding material. In some examples, the material may be configuredto change the surface charge of the active material. In some examples,the material may be configured to change the surface charge of thebinding material. In some examples, the material may comprise a couplingagent (e.g., an agent capable of enhancing adhesion or bonding betweentwo materials). For example, the coupling agent may be silane (e.g.,binary silicon-hydrogen compounds and compounds with four substituentson silicon, including organosilicon compounds). Examples of silanesinclude trichlorosilane (SiHCl₃), tetramethylsilane (Si(CH₃)₄), andtetraethoxysilane (Si(OC2H₅)₄)).

In some embodiments, the flowable liquid may comprise a materialconfigured to change the zeta potential of the active material. In someexamples, such a material may comprise a surfactant (e.g., a substanceor compound comprising a hydrophobic tail and a hydrophilic head).Examples of surfactants include sodium stearate,4-(5-dodecyl)benzenesulfonate, docusate (dioctyl sodium sulfosuccinate),alkyl ether phosphates, benzalkaonium chloride (BAC),perfluorooctanesulfonate (PFOS),(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol, Octyl phenol ethoxylate,and hexadecyltrimethylammonium bromide (CTAB). In some examples, such amaterial may comprise a dispersant (e.g., a substance or compound, whenadded to a suspension of particles, capable of improving the separationof the particles and preventing their settling or clumping). Examples ofdispersants include sodium pyrophosphate, ammonium citrate, sodiumcitrate, sodium tartrate, sodium succinate, glyceryl trioleate,phosphate ester, random copolymers, comb polymers, poly(acrylic acid)(PAA), poly(methacrylic acid) (PMAA), ammonium polyacrylate, sodiumpolyacrylate, sodium polysulfonate, and poly(ethylene imine). In someexamples, the dispersants may act sterically not only changing zetapotential. The surfactants may disperse and change/adjust surfacetension.

In some embodiments, in the flowable liquid, a mass ratio between theactive material and the binding material may be from 0.000001 to1000000, e.g., from 0.000001 to 0.000005, from 0.000005 to 0.00001, from0.00001 to 0.00005, from 0.00005 to 0.0001, from 0.0001 to 0.0005, from0.0005 to 0.001, from 0.001 to 0.005, from 0.005 to 0.01, from 0.01 to0.05, from 0.05 to 0.1, from 0.1 to 0.5, from 0.5 to 1, from 1 to 5,from 5 to 10, from 10 to 50, from 50 to 100, from 100 to 500, from 500to 1000, from 1000 to 5000, from 5000 to 10000, from 10000 to 50000,from 50000 to 100000, from 100000 to 500000, or from 500000 to 1000000.

In some embodiments, the flowable liquid may have a viscosity from 1 to2000 centipoise, e.g., from 3 to 1500, from 3 to 50, from 50 to 100,from 100 to 200, from 200 to 300, from 300 to 400, from 400 to 500, from500 to 600, from 600 to 700, from 700 to 800, from 800 to 900, from 900to 1000, from 1000 to 1100, from 1100 to 1200, from 1200 to 1300, from1300 to 1400, or from 1400 to 1500 centipoise.

In some embodiments, the nozzle 101 of FIG. 1 generates and dispensesdroplets 103 containing a homogenous mixture of one or more activematerials and a binding material. As described in further detail belowin connection with FIGS. 2-3 , each droplet 103 may self-assemble toform a continuous structure with many units 105 a, 105 b, where theactive material and the binding material self-segregate to form anon-uniform distribution of the active material and the binding materialin each of the units. The units may be in the form of a honeycomb cellas shown with unit 105 b, and in other embodiments the units may havefewer edges (or no edges) such as shown with unit 105 a.

The generated droplets 103 may have a volume suitable for manufacturingthe structure. In some embodiments, the generated droplets may have anaverage volume from 0.1 to 5000 picoliters, e.g., from 0.1 to 3000, from0.1 to 100, from 100 to 250, from 250 to 500, from 500 to 750, from 750to 1000, from 1000 to 1250, from 1250 to 1500, from 1750 to 2000, from2000 to 2250, from 2250 to 2500, from 2500 to 2750, from 2750 to 3000,from 1 to 100, from 1 to 80, from 1 to 60, from 1 to 50, from 2 to 50,from 3 to 50, from 3 to 10, from 5 to 15, from 10 to 20, from 15 to 25,from 20 to 30, from 25 to 35, from 30 to 40, from 35 to 45, or from 40to 50 picoliters. In some examples, the generated droplets may have anaverage volume from 0.1 to 3000 picoliters. In some examples, thegenerated droplets may have an average volume from 3 to 50 picoliters.

The method may further comprise controlling the sizes of the generateddroplets 103. In some embodiments, the sizes of the droplets may becontrolled by applying force to the flowable liquid. For example, theforce may be mechanical pressure, collision with another liquid orfluid, ultrasonic waves, electrical charge, or a combination thereof. Insome examples, the sizes of the droplets may be controlled by forcingthe flowable homogenous liquid through orifices or openings of differentsizes.

In some embodiments, the volume of the droplets may be controlled by adigitally controlled tool. During the manufacturing process, theposition of the droplets deposited on the surface may be controlled by adigitally controlled tool as well. In some examples, the droplets may begenerated and deposited by a printing technology (e.g., a 3D printingtechnology, drop-ondemand industrial inkjet printing technology, digitalprinting technology, or computer-controlled ink-jet printingtechnology), digital fabrication technology, or digital depositiontechnology. Examples of printing technologies include those described inHebner, TR et al., (1998) Appl.Phys. Lett., 72, 519-521 (1998),Blazdell, PF et al., Mater. Process. Technol., 99, 94-102 (2000),Jacobs, HO, Science, 291, 1763-1766 (2001), Zhao, Y et al., Electrochim.Acta, 51, 2639-2645 (2006), and Xu, F et al., Chem. Phys. Lett., 375,247-251 (2003), which are incorporated by reference herein in theirentireties. In some examples, the methods and compositions describedherein may allow a synthesis control of electrodes at the microscalelevel, and obtaining 3D structures which improve the batteryperformance.

While not illustrated in FIG. 1 , in some embodiments, the method mayfurther comprise polymerizing the binding material. For example, thebinding material may be polymerized by heat or irradiation. In someexamples, the polymerization may be performed after the binding materialand the active material self-segregate to fix the position ordistribution pattern of the binding material and/or the active material.

FIG. 2A shows a droplet containing a homogeneous liquid containing anactive material and a binding material, according to some embodiments.In some embodiments, a generated droplet 203 may comprise a plurality ofactive materials and/or a plurality binding materials. In the exampleshown in FIG. 2A, the droplet 203 contains a first active material 207a, a second active material 207 b, and a binding material 209, which areuniformly distributed in the droplet 203.

FIG. 2B illustrates self-segregation of the active material and thebinding material to form a non-uniform distribution of the activematerial and the binding material in a microstructure unit, according tosome embodiments. FIG. 2B shows that, after the droplet 203 is depositedon a support, the active materials 207 a-b and binding material 209self-segregate to form a non-uniform distribution of the active materialand the binding material in the microstructure unit 205 formed by thedroplet. As illustrated in FIG. 2B, the binding material 209 hasself-segregated from the active materials, and has accumulated primarilyat the edges of the microstructure unit 205.

In some embodiments a structure comprises a plurality of microstructureunits 205. The structure may comprise an active material and a bindingmaterial. The active material and the binding material mayself-segregate when being deposited on a surface or support when formingthe structure. When segregated from the active material, the bindingmaterial may accumulate at certain areas of the units. Similarly, whensegregated from the binding material, the active material may accumulateat certain areas of the units, which may be the same or different fromthe areas where the binding material accumulates. Such self-segregationof the active material and the binding material may cause non-uniformdistribution of the materials in the structure, which form amicrostructure comprising a plurality of units. The non-uniformdistribution may be controlled by the manufacturing process so that themicrostructure units have desired properties, e.g., a desired physical,thermal, chemical, catalytic, electrical, magnetic, radioactive,photonic, or biological property, or any combination thereof. Each ofthe microstructure units may comprise an active material and a bindingmaterial. In some embodiments, each of the units may comprise more thanone active material and/or more than one binding material.

FIG. 3 illustrates self-assembly and self-segregation of liquid dropletsto form a structure, according to some embodiments. FIG. 3 illustratesan example of self-assembly of the droplets 303 a-n occurring over time,beginning at time t₁ and ending at time t₄. The droplets 303 a n containa first active material 307 a, a second active material 307 b, and abinder material 309 in FIG. 3 . However, in other embodiments, there maybe only one active material and/or one binder material. In this example,t₁ illustrates the droplets 303 a-n shortly after deposition on asupport or surface as described above in connection with FIG. 1 . Asshown at times t₂ and t₃, the droplets 303 a-n begin to self-assemble toform a continuous structure. The self-assembly process may be guided bymanipulation of capillary flow and evaporation of the droplets 303 a-n.In addition, at times t₂ and t₃, the active material and the bindingmaterial self-segregate in each of the droplets as described above inconnection with FIGS. 2A-B. The process of self-assembly continues fromt₁ to t₄ to form a continuous structure comprising microstructure units305 a-n, where each microstructure unit contains a non-uniformdistribution of the active and the binding materials.

The self-assembly of the droplets may be driven by the reduction ofsurface energy. Droplets may tend to coalesce and self-assemble to formswith the lowest surface energy. The self-segregation in a mixture ofmaterials may be driven by surface charge properties. Coulombicrepulsion may dominate when the surface charges are similar leading toself-segregation. On the other hand, if surface charges are dissimilar,coulombic attraction may dominate, leading to selfcoalescence. The waysto alter surface charge properties of a material may be to introduce asurfactant to enhance steric hindrance or add a coupling agent such as asilane.

In some examples, the self-segregated binding material may accumulate atedges of the units. The active material may be distributed within anarea in each microstructure unit bounded by the respective unit. In someexamples, the active material may be distributed non-uniformly withinthe area of each unit.

FIGS. 4A-4C illustrate cross sections of microstructure units, accordingto some embodiments. In all the microstructure units 405 a-c in FIGS.4A-4C, the active materials 407 a-b accumulate at the center of the unitand the binding material 409 accumulates at the edges of the units. Theedge of the microstructure unit may be elevated (e.g., FIG. 4A), even(e.g., FIG. 4B), or lower (e.g., FIG. 4C) than the center of the unit.

The microstructure units may be three-dimensional open-ended cells. Insome embodiments, some or all of the microstructure units may comprisean area bounded by at least 3 sides, e.g., by 3, 4, 5, 6, 7, 8, 9, 10 ormore sides. In some examples, the lengths of the sides may besubstantially the same. In one example, a subset or all of themicrostructure units (e.g., a majority of the microstructure units inthe structure such as at least 50%, 60%, 70%, 80%, 90%, 95%, or 99% ofthe microstructure units in the structure) may comprise an area boundedby 6 sides. Such units may be bound by 6 sides with substantially thesame length, e.g., in the shape of honeycomb cells.

In some embodiments, the units may have an average diameter from 0.01 to3000 micrometers, e.g., from 0.02 to 2000, from 0.04 to 2000, from 0.04to 1500, from 0.04 to 1000, from 0.04 to 500, from 1 to 500, from 5 to500, from 10 to 500, from 20 to 500, from 25 to 500, from 25 to 100,from 40 to 80, from 50 to 70, from 45 to 55, from 50 to 60, from 55 to65, from 60 to 70, from 65 to 75, from 70 to 80, from 25 to 50, from 50to 100, from 100 to 150, from 150 to 200, from 200 to 250, from 250 to300, from 300 to 350, from 350 to 400, from 400 to 450, or from 450 to500, from 500 to 750, from 750 to 1000, from 1000 to 1250, from 1250 to1500, from 1500 to 1750, or from 1750 to 200 micrometers. In oneexample, the units may have an average diameter from 50 to 70micrometers, e.g., from 50 to 55, from 55 to 60, from 60 to 65, or from65 to 70 micrometers.

In some embodiments, the unit each microstructure in the structure mayhave a vertical aspect ratio (e.g., the ratio of the thickness to thediameter of the unit) equal to or greater than 1, e.g., equal to orgreater than 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.5, 4, 4.5,or 5.

In some embodiments, the structure may be a continuous structure. Thestructure may comprise a continuous layer (e.g., a continuously planarlayer). The layer may be along a planar surface of a support. In someembodiments, the structure may comprise a plurality of stacked layers(e.g., stacked planar layers).

FIG. 5 illustrates multiple layers of a structure, according to someembodiments. FIG. 5 illustrates a structure 530 with multiple layers 550a-n. Each layer 550 includes microstructure units including a firstactive material 507 a, a second active material 507 b, and a bindermaterial 509.

In some embodiments, the structure may comprise at least 2, 5, 10, 50,100, 150, 200, 250, 300, 350 stacked layers (e.g., stacked planarlayers). In some examples, the first layer of the stacked layers maycomprise an active material that is the same as an active material of asecond layer of the stacked layers, and the first layer has differentparticle size characteristics than the second layer of the plurality ofstacked layers. In some examples, the average diameters of the units onat least two layers may be different. In some examples, the averagediameters of the units on at least two layers may be the same. In someexamples, a first layer of the plurality of stacked layers may comprisea material that is different than one or more materials in a secondlayer of the plurality of stacked layers, or the same active materialhaving a different physical, chemical, catalytic, electrical, magnetic,radioactive, photonic, biological, or combinations thereofcharacteristic in a second layer of the plurality of stacked layers.

The active material may be any material that serves a function. Theactive material may provide a function of the structure. For example,the active material may impart a physical, thermal, chemical, catalytic,electrical, magnetic, radioactive, photonic, or biological property, ora combination thereof to the structure. In one example, the activematerial imparts a physical property to the structure (e.g., materialdensities, porosities, strength, shapes, etc.). In another example, theactive material may impart a thermal property to the structure. Inanother example, the active material may impart a chemical property tothe structure. In another example, the active material may impart acatalytic property to the structure. In another example, the activematerial may impart an electrical property to the structure. In anotherexample, the active material may impart a magnetic property to thestructure. In another example, the active material may impart aradioactive property to the structure. In another example, the activematerial may impart a photonic property to the structure. In anotherexample, the active material may impart a biological property to thestructure.

In some embodiments, the active material may intercalate ions (e.g.,lithium ions) or have a conversion reaction in the presence of ions(e.g., lithium ions). For example, the active material may facilitatethe chemical reaction in which ions (e.g., lithium ions) are insertedinto a host matrix with essential retention of the crystal structure. Insome embodiments, the active materials may comprise transition metals(e.g., nickel, cobalt, manganese, copper, zinc, vanadium, chromium,iron), and their oxides, phosphates, phosphites, sulfides, andsilicates, as well as alkalines and alkaline earth metals, aluminum,aluminum oxides, and aluminum phosphates. Examples of active materialsinclude LiCoO₂, LiMn₂O₄, LiFePO₄, LiNi_(⅓)Mn_(⅓)Co_(⅓)O₂.LiNi_(0.8)Co_(0.15)Al_(0.05)O₂, LiC₆, Li₄Ti₅O₁₂, LiNiCoAlO₂, LiNiCoMnO₂,LiNi_(0.5)Mn_(1.5)O₄, Li₂TiO₃, Li(Ni_(0.5)Mn_(0.5))O₂, Li₂S, graphite(artificial or natural), hard carbon, titanate, titania, transitionmetals in general, halides, and/or chalcogenides, silicon, and otherelements in group 14 (e.g., tin, germanium, etc.). In some examples, theactive material may comprise LiFePO₄. In some embodiments, the activematerial may be an insulator.

In some embodiments, the active material may be an active catalystcapable of causing or accelerating a chemical reaction betweenreactants, and the reactants and/or the products of the chemicalreaction may be transported through the microstructure units. In someexamples, the catalyst may be an enzyme or a chemical catalyst.

In some embodiments, the active material may be an active adsorbentcapable of selectively binding to an adsorbate, and a medium carryingthe adsorbate may be transported through the microstructure units. Anactive adsorbent may be a material (e.g., solid or semi-solid material)capable of bind to (e.g., selectively bind to) an adsorbate, which maybe a gas, or dissolved substance or suspended particle in a solution, ora mixture thereof. In some embodiments, the active adsorbent may give aresponse when binding to an adsorbate. Such response may be a change inphysical, chemical, electrical, optical, or magnetic properties, or anycombination thereof of the adsorbent. In some examples, such a responsemay be a measurable response, e.g., a light, sound, electrical signal.

In some embodiments, the active material may be an active carrier of acompound, and wherein at least a part of the compound may be released ina controlled manner when contacted with a transport medium, and thetransport medium may be transported through the microstructure units.For example, the transport medium may be capable of transporting thecompound through the microstructure units. The transport medium may bein a gaseous, liquid or solid state. In one example, the transportmedium may be a body fluid (e.g., blood, urine, or saliva).

In some embodiments, the active material may be an active carrier of aphoto-sensitive compound, and the photo-sensitive compound may give anoptical response when excited photonically. Examples of photo-sensitivecompounds include fluorescent dyes.

In some embodiments, the active material may be an active carrier of amagnetic-sensitive compound. The magnetic-sensitive compound may give amagnetic response when excited magnetically. In some embodiments, theactive material may be an active carrier of a pigment. The pigment mayhave an optical response (e.g., generating an optical signal) whenexcited (e.g., with visible, ultraviolet or infrared light).

The binding material may be any material capable of facilitating theadherence of particles in the active material in the structure. In someexamples, the binding material may comprise an organic material. In someexamples, the binding material may comprise an inorganic material. Insome examples, the binding material may comprise a combination ormixture of an organic material and an inorganic material. In oneexample, the binding material may be a polymer, e.g., polyvinylidenedifluoride (PVdF), carboxyl-methyl cellulose (CMC), styrenebutadienerubber (SBR), or a mixture or combination thereof.

The structure may comprise one or more additional components needed fora particular function. In some embodiments, the structure may compriseone or more conductive materials. Examples of conductive materialsinclude carbon (e.g., nanometer-sized carbon) such as carbon black,graphite, ketjen black, a graphitic carbon, a low dimensional carbon(e.g., carbon nanotubes), and/or a carbon fiber.

FIG. 6 is a topographical optical image of a structure, according tosome embodiments. FIG. 6 shows an optical picture (taken with an opticalmicroscope) of an exemplary structure comprising microstructure units,e.g., microstructure units in the shape of honeycombs. The picture istaken of a top view of a structure, such as the structure describedabove in connection with FIG. 5 .

FIG. 7 is a topographical scanning electron micrograph image of astructure, according to some embodiments. The structure shown in FIG. 7is a structure coated on a lithium ion cathode containing multiplemicrostructure units with a non-uniform distribution of active andbinding materials. In each of the microstructure units, the activematerial and the binding material self-segregated, forming a non-uniformdistribution where the binding material aggregated along the edges ofthe units. As shown in FIG. 7 , in the microstructure units, there isabout 40% more binding material at the edges of the units than in thecenter of the units.

The structure in FIG. 7 may be manufactured with the compositioncomprising the components in Table 1 below and the structure maycomprise LiFePO4 (the active material), Triton-X100, carbon black, andPVdF Solef 5130 (the binding material).

In some examples, the flowable liquid may comprise the components inTable 1 below.

Table 1 Components %wt Target Weight (g) (~60mL) LiFePO₄ (activematerial) 3 1.94 N-Methyl-2-pyrrolidone (NMP) 95.66 61.8 Triton-X100 10.65 Carbon Black (CB) 0.17 0.11 PVdF Solef 5130 (binding material) 0.170.11

For comparison, FIGS. 8A and 8B are pictures of material distributionsin commercial electrodes made with prior art techniques, such as bladecasting, die casting, tape casting, or slotdie coating technology. FIG.8A is a topographical scanning electron micrograph image of thecommercial electrode. FIG. 8B illustrates the energy dispersivespectroscopy of the commercial electrode captured using a scanningelectron microscope (SEM). As illustrated in FIGS. 8A-8B, there is ahomogeneous uniform distribution of binding and active materials, whichis different from the non-uniform distribution of the materials in thestructure according to the present disclosure, e.g., the structure shownin FIG. 7 .

FIG. 9A is a topographical scanning electron micrograph image of astructure, according to some embodiments. FIG. 9B illustrates thefluorine channel of an energy dispersive spectroscopy of the structureshown in FIG. 9A, according to some embodiments. Fluorine is onlypresent in the PVDF binding material used in this sample. FIGS. 9A and9B show another example of the structure with the binding materialaccumulated at the edges of the microstructure units. FIGS. 9A and 9Billustrate the top layer of an electrode microstructure.

FIG. 10A illustrates a topographical scanning electron micrograph imageof a structure, according to some embodiments. FIG. 10B illustrates anenergy dispersive spectroscopy of the structure shown in FIG. 10A,according to some embodiments. FIGS. 10A and 10B show yet anotherexample of the structure with the binding material accumulated at theedges of the microstructure units. In this structure, the activematerial also accumulates at the edges but within the boundaries formedby the binding material, e.g., the microstructure units are “hollow”(referring to a higher material density at the edge than the center of amicrostructure unit). The lighter gray areas in FIG. 10B illustrate theionic properties of the active material.

FIG. 11 shows a schematic of the “hollow” structure in FIGS. 10A and10B. In some examples, the structure 1130 may comprise a conductivematerial that also distributes along the edges of the units but withinthe boundaries formed by the binding material. In some examples, the“hollow” structure may have multiple layers 1150 a-n of microstructureunits as shown in FIG. 11 . The microstructure units of FIG. 11 includea first active material 1107 a, a second active material 1107 b, and abinder material 1109.

FIG. 12 shows a schematic of another example of the structures accordingto the present disclosure. The structure 1230 may comprise a bindingmaterial but not active material. The binding material may accumulate atthe edges of the microstructure units. The structure 1230 may compriseone or more layers, e.g., a plurality of layers 1205 a-n.

The distribution of the active material (e.g., within or at the edges ofthe microstructure units) may be controlled by the manufacturingprocess. In some embodiments, the distribution of the active materialmay be controlled with different drying processes. For example,different infrared (IR) protocols may be used. FIG. 13 shows thatdifferent distributions of the active material in the microstructureunits resulted from different infrared exposures. In the drying process,with a lower IR exposure, the active material accumulated at the edgesof the resulting microstructure units (e.g., forming “hollow” units),while with a lower IR infrared exposure the active material accumulatedwithin the edges of the resulting microstructure units (e.g., forming“filled” units).

FIG. 14 shows a flowchart of a method 1400 of manufacturing a structure,according to some embodiments. The method 1400 comprises Steps 1402,1404, and 1406. Step 1402 comprises obtaining a flowable liquidcomprising a homogenous mixture of an active material and a bindingmaterial. Step 1404 comprises generating a plurality of droplets fromthe flowable liquid. Step 1406 comprises depositing the plurality ofgenerated droplets on a support. In some embodiments, the continuousstructure may comprise a plurality of microstructure units, and theactive material and the binding material self-segregate to form anon-uniform distribution of the active material and the binding materialin each of the units.

FIG. 15 shows a flowchart of a method 1500 of manufacturing a structure,according to some embodiments. The method 1400 comprises Steps 1502,1504, and 1506. Step 1502 comprises obtaining a flowable liquidcomprising a homogenous binding material. Step 1504 comprises generatinga plurality of droplets from the flowable liquid. Step 1506 comprisesdepositing the plurality of generated droplets on a support. In someembodiments, the plurality of droplets may self-assemble to form acontinuous structure, wherein the continuous structure comprises aplurality of microstructure units, and wherein the binding materialself-segregates to form a non-uniform distribution of the bindingmaterial in each of the units.

In another aspect, the present disclosure provides an article comprisingthe structure described herein. In some examples, the article maycomprise a support coated with the structure. Such support may comprisea metallic film, a metallized plastic film, metallized polymer film,glass film, ceramic film, polymer film, or paper. In one example, thesupport may be a metallic film. In another example, the support may be ametallized film. In another example, the support may be a plastic film.In another example, the support may be a glass film. In another example,the support may be a ceramic film. In another example, the support maybe a polymer film. In another example, the support may be paper. In someexamples, the article may comprise a component filled with a materialwith the structure described herein.

In some embodiments, the article may be an electrochemical cell. Theelectrochemical cell may comprise one or more electrodes comprising(e.g., coated with) the structure. In some examples, the electrode maycomprise the structure with microstructure units, each of which isbounded by 6 sides, e.g., in a honeycomb shape. The electrode maycomprise multiple layers of the structure. In some examples, at leasttwo of the layers may be offset.

In some embodiments, the structure may be used to coat electrodes toimprove the performance of batteries. In some examples, aninkjet-printed coffee-stain liquid droplet effect may be used to controlthe placement of the active material and the binding material on asubstrate, thereby allowing precision control of the electrodemicrostructure. In some examples, the structure coating the electrodemay have a microstructure in the form of a honeycomb, e.g., with thebinding material forming a honeycomb shape and the area within thehoneycomb units filled with the active material. Such a structure may belayered in various ways to optimize electrochemical cell performance fordifferent applications. In some examples, the electrode may comprise asingle or a plurality of layers of printed honeycomb structures.

The microstructure units in the structure on the electrode may havecertain physical properties such as material densities, porosities, andbinding material placement. In some embodiments, such properties mayenhance the mass transport of ions (e.g., lithium ions) through theelectrode, which may result in a higher power density when compared toelectrodes using the same material but without the microstructure units.In some embodiments, the structure may comprise a secondary porenetwork. Such a network may be capable of modifying ion transport withinthe microstructure, e.g., increasing the ion diffusion (e.g., lithiumion diffusion) through the electrode.

In some embodiments, the structure with the microstructure units may bestronger than the amorphous structure, leading to stronger batteryelectrodes with reduced or no electrode cracking. Since electrodecracking is one of the most important issues affecting battery life, theelectrode with the structure described herein may have longer batterycycle life, when compared to electrodes with the same material butwithout the microstructure features.

In some embodiments, more than one component of the electrochemical cellmay comprise the structure described herein. For example, cathode(s),anode(s), separator(s), solid or semi-solid electrolyte(s), otherbattery chemistries or electrical device(s), or any combination thereof,may comprise the structure (e.g., coated by the structure) for desiredfunctions. For example, cathode(s), anode(s), separator(s), solid orsemi-solid electrolyte(s), other battery chemistries or electricaldevice(s), or any combination thereof, may comprise the structure may beused as the support when making the structure.

As used herein, the singular forms “a,” “an,” and “the” include bothsingular and plural referents unless the context clearly dictatesotherwise.

The term “optional” or “optionally” means that the subsequent describedevent, circumstance or substituent may or may not occur, and that thedescription includes instances where the event or circumstance occursand instances where it does not.

The recitation of numerical ranges by endpoints includes all numbers andfractions subsumed within the respective ranges, as well as the recitedendpoints.

The term “about” in relation to a reference numerical value and itsgrammatical equivalents as used herein can include the numerical valueitself and a range of values plus or minus 10% from that numericalvalue. For example, the amount “about 10” includes 10 and any amountfrom 9 to 11.

The term “substantially the same” or “essentially the same” refers to asufficiently high degree of similarity between two or more numericvalues, compositions or characteristics that one of skill in the artwould consider the difference between these values, compositions orcharacteristics to be of little or no statistical significance withinthe context of the property being measured. The difference between twosubstantially the same numeric values may, for example, be less than10%.

The term “exemplary” is used herein to mean serving as an example,instance, or illustration. Any aspect or design described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other aspects or designs. Rather, use of the wordexemplary is intended to present concepts in a concrete fashion.

Various embodiments are described hereinafter. It should be noted thatthe specific embodiments are not intended as an exhaustive descriptionor as a limitation to the broader aspects discussed herein. One aspectdescribed in conjunction with a particular embodiment is not necessarilylimited to that embodiment and can be practiced with any otherembodiment(s). Reference throughout this specification to “oneembodiment,” “an embodiment,” “an example embodiment,” means that aparticular feature, structure or characteristic described in connectionwith the embodiment is included in at least one embodiment of thepresent invention. Thus, appearances of the phrases “in one embodiment,”“in an embodiment,” or “an example embodiment” in various placesthroughout this specification are not necessarily all referring to thesame embodiment, but may. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner,as would be apparent to a person skilled in the art from thisdisclosure, in one or more embodiments. Furthermore, while someembodiments described herein include some but not other featuresincluded in other embodiments, combinations of features of differentembodiments are meant to be within the scope of the invention. Forexample, in the appended claims, any of the claimed embodiments can beused in any combination.

All publications, published patent documents, and patent applicationscited herein are hereby incorporated by reference to the same extent asthough each individual publication, published patent document, or patentapplication was specifically and individually indicated as beingincorporated by reference.

Various modifications and variations of the described methods,compositions, and kits of the invention will be apparent to thoseskilled in the art without departing from the scope and spirit of theinvention. Although the invention has been described in connection withspecific embodiments, it will be understood that it is capable offurther modifications and that the invention as claimed should not beunduly limited to such specific embodiments. Indeed, variousmodifications of the described modes for carrying out the invention thatare obvious to those skilled in the art are intended to be within thescope of the invention. This application is intended to cover anyvariations, uses, or adaptations of the invention following, in general,the principles of the invention and including such departures from thepresent disclosure come within known customary practice within the artto which the invention pertains and may be applied to the essentialfeatures herein before set forth.

What is claimed is:
 1. A structure comprising a plurality ofmicrostructure units, wherein each of the units comprises a bindingmaterial self-segregated from an active material to form a non-uniformdistribution of the binding material and the active material in each ofthe units.
 2. The structure of claim 1, wherein the active materialimparts a physical, thermal, chemical, catalytic, electrical, magnetic,radioactive, photonic, biological property, or a combinations thereof tothe structure.
 3. The structure of claim 1, wherein the active materialis distributed within an area in each microstructure unit bounded by therespective unit.
 4. The structure of claim 3, wherein the activematerial is distributed non-uniformly within the area of each unit. 5.The structure of claim 1, wherein the binding material comprises anorganic material, an inorganic material, or a combination thereof. 6.The structure of claim 1, wherein the binding material self-segregatesto accumulate at edges of the units.
 7. The structure of claim 1,wherein the active material accumulates adjacent to a boundary formed bythe binding material, and a center of a respective unit is hollow andcontains no active material or binding material.
 8. The structure ofclaim 1, wherein the units have an average diameter from 0.04micrometers to 2000 micrometers.
 9. The structure of claim 1, whereinthe structure comprises a continuous planar layer.
 10. The structure ofclaim 1, wherein the structure comprises a plurality of stacked planarlayers.
 11. The structure of claim 10, wherein a first layer comprisesan active material that is the same as an active material of a secondlayer of the plurality of stacked layers, and the first layer hasdifferent particle size characteristics than the second layer of theplurality of stacked layers.
 12. The structure of claim 1, wherein eachmicrostructure unit comprises an area bounded by at least three sides.13. The structure of claim 1, wherein a subset of the plurality ofmicrostructure units comprise an area bounded by six sides to form ahoneycomb cell.
 14. The structure of claim 13, wherein the subsetcomprises a majority of the plurality of microstructure units.
 15. Thestructure of claim 1, wherein each unit has a vertical aspect ratioequal or greater than
 1. 16. The structure of claim 1, wherein theactive material intercalates lithium ions or has a conversion reactionin the presence of lithium ions.
 17. The structure of claim 1, whereinthe active material is an active catalyst capable of causing oraccelerating a chemical reaction between reactants and wherein thereactants and a product of the chemical reaction are transported throughthe microstructure units.
 18. The structure of claim 1, wherein theactive material is an active adsorbent capable of selectively binding toan adsorbate and wherein a medium carrying the adsorbate is transportedthrough the microstructure units.
 19. The structure of claim 18, whereinthe active adsorbent gives a response when binding to an adsorbate, andwherein the response comprises a change in a physical, chemical,electrical, optical and magnetic property of the active adsorbent. 20.The structure of claim 1, wherein the active material is an activecarrier of a compound, and wherein at least a part of the compound canbe released in a controlled manner when contacted with a transportmedium, and wherein the transport medium is transported through themicrostructure units.
 21. The structure of claim 1, wherein the activematerial is an active carrier of a photo-sensitive compound, and whereinthe photo-sensitive compound gives an optical response when excitedphotonically.
 22. The structure of claim 1, wherein the active materialis an active carrier of a magnetic-sensitive compound, and wherein themagnetic-sensitive compound gives a magnetic response when excitedmagnetically.
 23. The structure of claim 1, wherein the active materialis an active carrier of a pigment, and wherein the pigment gives anoptical response when excited with visible, ultraviolet or infraredlight.
 24. The structure of claim 1, wherein the active material impartsan electrical property to the continuous structure, and the activematerial comprises one or more of a conductor, semiconductor, orinsulator.
 25. An article of manufacture, the article comprising: astructure comprising a plurality of microstructure units, wherein eachof the units comprises a binding material self-segregated from an activematerial to form a non-uniform distribution of the binding material andthe active material in each of the units; and a support coated by thestructure.
 26. The article of claim 25, wherein the support comprises ametallic film, metallized plastic film, metallized polymer film, glassfilm, ceramic film, polymer film, or paper.
 27. The article of claim 25,wherein the article is an electrochemical cell.
 28. The article of claim27, wherein the electrochemical cell comprises an electrode comprisingthe structure.
 29. The article of claim 25, wherein the structurecomprises a conductive material.
 30. The article of claim 25, whereinthe support is comprised in a cathode, anode, separator, solidelectrolyte, or semi-solid electrolyte.